# Volatility
# Copyright (C) 2008-2013 Volatility Foundation
# Copyright (C) 2011 Jamie Levy (Gleeda) <jamie@memoryanalysis.net>
#
# This file is part of Volatility.
#
# Volatility is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Volatility is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Volatility.  If not, see <http://www.gnu.org/licenses/>.
#

"""
@author:       Jamie Levy (gleeda)
@license:      GNU General Public License 2.0
@contact:      jamie@memoryanalysis.net
@organization: Volatility Foundation
"""

import volatility.plugins.registry.registryapi as registryapi
from volatility.renderers import TreeGrid
import volatility.debug as debug
import volatility.utils as utils
import volatility.obj as obj
import volatility.plugins.common as common
import volatility.addrspace as addrspace

# Structures taken from the ShimCache Whitepaper: https://blog.mandiant.com/archives/2459

#### SHIMRECS ####

shimrecs_type_xp = {
    'ShimRecords' : [ None, {
        'Magic' : [ 0x0, ['unsigned int']], #0xDEADBEEF
        'NumRecords' : [ 0x8, ['short']],
        'Entries' : [0x190, ['array', lambda x: x.NumRecords, ['AppCompatCacheEntry']]],
    } ],
}

shimrecs_type_2003vista = {
    'ShimRecords' : [ None, {
        'Magic' : [ 0x0, ['unsigned int']], #0xBADC0FFE
        'NumRecords' : [ 0x4, ['int']],
        'Entries' : [0x8, ['array', lambda x: x.NumRecords, ['AppCompatCacheEntry']]],
    } ],
}

shimrecs_type_win7 = {
    'ShimRecords' : [ None, {
        'Magic' : [ 0x0, ['unsigned int']], #0xBADC0FFE
        'NumRecords' : [ 0x4, ['int']],
        'Entries' : [0x80, ['array', lambda x: x.NumRecords, ['AppCompatCacheEntry']]],
    } ],
}

#### APPCOMPAT TYPES ####

appcompat_type_xp_x86 = {
    'AppCompatCacheEntry' : [ 0x228, {
        'Path' : [ 0x0, ['NullString', dict(length = 0x208, encoding = 'utf8')]],
        'LastModified' : [ 0x210, ['WinTimeStamp', dict(is_utc = True)]],
        'FileSize': [0x218, ['long long']],
        'LastUpdate' : [ 0x220, ['WinTimeStamp', dict(is_utc = True)]],
    } ],
}

appcompat_type_2003_x86 = {
    'AppCompatCacheEntry' : [ 0x18, {
        'Length' : [ 0x0, ['unsigned short']],
        'MaximumLength' : [0x2, ['unsigned short']],
        'PathOffset' : [ 0x4, ['unsigned int']],
        'LastModified' : [ 0x8, ['WinTimeStamp', dict(is_utc = True)]],
        'FileSize': [0x10, ['_LARGE_INTEGER']],
    } ],
}

appcompat_type_vista_x86 = {
    'AppCompatCacheEntry' : [ 0x18, {
        'Length' : [ 0x0, ['unsigned short']],
        'MaximumLength' : [0x2, ['unsigned short']],
        'PathOffset' : [ 0x4, ['unsigned int']],
        'LastModified' : [ 0x8, ['WinTimeStamp', dict(is_utc = True)]],
        'InsertFlags' : [0x10, ['unsigned int']],
        'Flags' : [0x14, ['unsigned int']],
    } ],
}

appcompat_type_win7_x86 = {
    'AppCompatCacheEntry' : [ 0x20, {
        'Length' : [ 0x0, ['unsigned short']],
        'MaximumLength' : [0x2, ['unsigned short']],
        'PathOffset' : [ 0x4, ['unsigned int']],
        'LastModified' : [ 0x8, ['WinTimeStamp', dict(is_utc = True)]],
        'InsertFlags' : [0x10, ['unsigned int']],
        'ShimFlags' : [0x14, ['unsigned int']],
        'BlobSize' : [0x18, ['unsigned int']],
        'BlobOffset' : [0x1c, ['unsigned int']],
    } ],
}

appcompat_type_2003_x64 = {
    'AppCompatCacheEntry' : [ 0x20, {
        'Length' : [ 0x0, ['unsigned short']],
        'MaximumLength' : [0x2, ['unsigned short']],
        'PathOffset' : [ 0x8, ['unsigned long long']],
        'LastModified' : [ 0x10, ['WinTimeStamp', dict(is_utc = True)]],
        'FileSize': [0x18, ['_LARGE_INTEGER']],
    } ],
}

appcompat_type_vista_x64 = {
    'AppCompatCacheEntry' : [ 0x20, {
        'Length' : [ 0x0, ['unsigned short']],
        'MaximumLength' : [0x2, ['unsigned short']],
        'PathOffset' : [ 0x8, ['unsigned int']],
        'LastModified' : [ 0x10, ['WinTimeStamp', dict(is_utc = True)]],
        'InsertFlags' : [0x18, ['unsigned int']],
        'Flags' : [0x1c, ['unsigned int']],
    } ],
}

appcompat_type_win7_x64 = {
    'AppCompatCacheEntry' : [ 0x30, {
        'Length' : [ 0x0, ['unsigned short']],
        'MaximumLength' : [0x2, ['unsigned short']],
        'PathOffset' : [ 0x8, ['unsigned long long']],
        'LastModified' : [ 0x10, ['WinTimeStamp', dict(is_utc = True)]],
        'InsertFlags' : [0x18, ['unsigned int']],
        'ShimFlags' : [0x1c, ['unsigned int']],
        'BlobSize' : [0x20, ['unsigned long long']],
        'BlobOffset' : [0x28, ['unsigned long long']],
    } ],
}

class ShimCacheTypesXPx86(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 5,
                  'minor': lambda x: x == 1,
                  'memory_model': lambda x: x == '32bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_xp)
        profile.vtypes.update(appcompat_type_xp_x86)


class ShimCacheTypes2003x86(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 5,
                  'minor': lambda x: x == 2,
                  'memory_model': lambda x: x == '32bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_2003vista)
        profile.vtypes.update(appcompat_type_2003_x86)

class ShimCacheTypesVistax86(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 6,
                  'minor': lambda x: x == 0,
                  'memory_model': lambda x: x == '32bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_2003vista)
        profile.vtypes.update(appcompat_type_vista_x86)

class ShimCacheTypesWin7x86(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 6,
                  'minor': lambda x: x == 1,
                  'memory_model': lambda x: x == '32bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_win7)
        profile.vtypes.update(appcompat_type_win7_x86)

class ShimCacheTypes2003x64(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 5,
                  'minor': lambda x: x == 2,
                  'memory_model': lambda x: x == '64bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_2003vista)
        profile.vtypes.update(appcompat_type_2003_x64)

class ShimCacheTypesVistax64(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 6,
                  'minor': lambda x: x == 0,
                  'memory_model': lambda x: x == '64bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_2003vista)
        profile.vtypes.update(appcompat_type_vista_x64)

class ShimCacheTypesWin7x64(obj.ProfileModification):
    before = ['WindowsObjectClasses']
    conditions = {'os': lambda x: x == 'windows',
                  'major': lambda x: x == 6,
                  'minor': lambda x: x == 1,
                  'memory_model': lambda x: x == '64bit'}
    def modification(self, profile):
        profile.vtypes.update(shimrecs_type_win7)
        profile.vtypes.update(appcompat_type_win7_x64)


class ShimCache(common.AbstractWindowsCommand):
    """Parses the Application Compatibility Shim Cache registry key"""
    def __init__(self, config, *args, **kwargs):
        self._addrspace = None
        common.AbstractWindowsCommand.__init__(self, config, *args, **kwargs)

    @staticmethod
    def is_valid_profile(profile):
        return profile.metadata.get('os', 'unknown').lower() == 'windows'

    @staticmethod
    def remove_unprintable(item):
        return ''.join([str(c) for c in item if (ord(c) > 31 or ord(c) == 9) and ord(c) <= 126])

    @staticmethod
    def get_entries(addr_space, regapi):

        regapi.reset_current()
        currentcs = regapi.reg_get_currentcontrolset()
        if currentcs == None:
            currentcs = "ControlSet001"

        version = (addr_space.profile.metadata.get('major', 0),
                   addr_space.profile.metadata.get('minor', 0))
        xp = False

        if version <= (5, 1):
            key = currentcs + "\\Control\\Session Manager\\AppCompatibility"
            xp = True
        else:
            key = currentcs + "\\Control\\Session Manager\\AppCompatCache"

        data_raw = regapi.reg_get_value('system', key, "AppCompatCache")
        if data_raw == None or len(data_raw) < 0x1c:
            debug.warning("No ShimCache data found")
            raise StopIteration

        bufferas = addrspace.BufferAddressSpace(addr_space.get_config(), data = data_raw)
        shimdata = obj.Object("ShimRecords", offset = 0, vm = bufferas)
        if shimdata == None:
            debug.warning("No ShimCache data found")
            raise StopIteration

        for e in shimdata.Entries:
            if xp:
                yield e.Path, e.LastModified, e.LastUpdate
            else:
                yield ShimCache.remove_unprintable(bufferas.read(int(e.PathOffset), int(e.Length))), e.LastModified, None

    def calculate(self):
        addr_space = utils.load_as(self._config)
        regapi = registryapi.RegistryApi(self._config)

        for entry in self.get_entries(addr_space, regapi):
            yield entry

    def unified_output(self, data):
        # blank header in case there is no shimcache data
        return TreeGrid([("Last Modified", str),
                       ("Last Update", str),
                       ("Path", str),
                      ], self.generator(data))

    def generator(self, data):
        for path, lm, lu in data:
            if lu:
                yield (0, [str(lm), str(lu), str(path).strip()])
            else:
                yield (0, [str(lm), "-", str(path).strip()])
